Liquid oxygen apparatus



Dee. 12, 1933. E. G. HlcKLlNG LIQUID OXYGEN APPARATUS Filed April 20,1931 INVENTOR:

ATTORNEYs Patented Dec. 12, 1933 LIQUID OXYGEN APPARATUS Ewart G.Hickling, Buffalo, N. Y., assignor to The Linde Air Products Company, acorporation of Ohio Application April 20, 1931. Serial No. 531,588

s claims.

'I'his invention relates to a liquid oxygen apairplanes as a means forsupplying oxygen gas for breathing purposes while flying at highaltitudes.

It is well known that at altitudes of approximately 15,000 feet andhigher, the atmosphere becomes too rareiled to sustain consciousness,and an additional supply of oxygen must be provided for aviatorsreaching such heights. The necessary oxygen supply is usually providedby carrying it in gaseous form under high pressure in heavy cylinders,the weight of each cylinder being some six times that of the oxygenwhich it contains. This cylinder Weight added to the plane load becomesa serious handicap, especially when it is necessary to carry the largequantities of oxygen required for attaining extremely high altitudes orfor other long sustained flight. At best a four hour supply is about allthat it is possible to carry in this manner. Furthermore, the gas underpressure contains as a rule a certain amount of moisture.

Due to the temperature of the atmosphere, and the coldness produced byexpansion of the gas, this moisture often freezes in the regulator andcauses a partial or complete cut-off of the oxygen supply.

In accordance with my invention I propose to use liquid oxygen as thesource of gas supply, whereby the serious disadvantages of carrying theoxygen in the gaseous form are greatly alleviated. I have provided asimple and eiiicient liquid oxygen apparatus which is light in weight,and will provide a continuous flow of dry oxygen gas to the occupants ofthe plane whenever' desired. Much larger supplies of oxygen may besafely carried with this apparatus, and the gas given oil is suicientlyfree from moisture to eliminate the hazard of freezing in the deliverypipe or in the regulating mechanism, if used.

The advantages of my invention will be evident from a description of theaccompanying drawing showing one embodiment thereof,

wherein Fig. 1 is a plan view of one type of apparatus.

Fig. 2 is an end elevation ofthe container and support.

Fig. 3 is a section on the une rrr-m of Fig.

tainer capable of withstanding about .5 lbs. gage pressure is suitable.'I'he container is suspended in a gimbal comprising the pivots 3 in acir- (Cl. 12S- 140) cular frame 4, the frame being pivoted at 5 to thebracket supports 6 which are rigidly attached to the plane. Thesupporting axis of the container and that of the frame 4 are at rightangles to each other and ball bearings, as shown in Fig. 00 3, are usedat all points of support. Thus no matter what position the airplane mayassume, the container always remains in an upright position. A fillercap 7 is provided in the top of the container, and the gas outlet pipe 8also leads 65 out of the top portion. The safety valve 9 acts to preventexcessive pressure ,within the container. The circular frame 4 is hollowso that gas may ow from the container through the pipe 8, through thebearing 3, a portion of the `circular frame and the bearing 5, to thepipe 10 which leads to the point where the oxygen is to be used.

A gas tight connection is provided for the filler cap 7 and this cap istightened into place im- 75 mediately after filling the container. Thusall gas evaporated from the liquid oxygen will pass through the outletpipe 8 and ultimately to the point of use, where a regulator may beprovided to control the rate vof now. The normal evaporation of theliquid gas will not in most cases be suiiicient for the needs of thepilot, and heating means are therefore -provided to stimulateevaporation. This consists of a heating coil 12 within the container,which is connected through the bearings 3 and 5 opposite the gas outletline and the hollow frame 4 to the pipe 14 leading to the funnel 15.This funnel is mounted on the exhaust pipe 16 leading from the engine ofthe plane. Air collected in the funnel is warmed by the heat of theexhaust pipe, and the amount of heat delivered to the coil 12 isregulated by the valve 17. Coiling the oxygen delivery -pipe 10 aboutthe warm air pipe 14, as shown at 18, will serve to aid in removing thechill from the gas before it passes to the user.

Details of the bearing construction of one of the pivots 3 is shown inFig. 3, and a similar arrangement is used at all points of support. Thehollow cylindrical rod 19 connects at one end with the container 2, andat the other end projects into the casing 21, having a chamber therein.At a necked portion of the chamber are mounted the ball bearings 22 onwhich the rod 19 revolves.

-The leather disc 23, attached to the end of the rod 165 19, acts toprevent passage of oil from the bearings into the chamber, and alsoprevents any leakage of gas from the chamber. The circular frame 4connects with the chamber of the casing 21, and, as previouslyexplained, acts as a passage for gas,

or warm air, from the pivots 3 to 5. The pivots 5 differ from the onehere shown only in the fact that the gas outlet line in one instance,and the warm air line in the other, rather than the circular frame 4,connect with the casing 21. Pivots of this nature will permit acontinuous free flow of gas no matter what position the circular frame 4or the support brackets 6 may assume with respect to the container,which always remains upright.

As much of the apparatus as possible is preferably made of aluminum oran aluminum alloy. This additionally lightens the load on the plane. Thesize of the container may vary as desired, and the one represented herehas a capacity of 10 liters of liquid oxygen. A container of this size,Weighing approximately 21 pounds, will easily carry 15 pounds of liquidoxygen, an amount generally considered sufficient for a flight of aboutfour hours at an altitude of around 30,000 feet. The combined weight ofthe container, the liquid oxygen, and the other parts of the apparatuswill add only about pounds to the total load of the plane. To carry anequivalent amount of oxygen in the form of the compressed gas wouldrequire ten cylinders weighing about 17 pounds apiece, which, togetherwith the oxygen, would present a total additional load of 185 pounds.Thus a saving in weight of 135 pounds is provided for a total oxygensupply of about l5 pounds. Where larger quantities of gas are desired,the saving in Weight is still greater, since the larger size liquidoxygen containers weigh less in proportion to the weight of liquid theycontain than do the smaller l ones.

Another advantage of this type of apparatus, as

' previously mentioned, resides in the fact that the gas given off fromthe liquid oxygen is exceedingly dry as compared with that obtainablefrom a high pressure cylinder source. There is therefore no danger ofthe oxygen line freezing up and cutting-off the oxygen supply in amanner which has heretofore happened with the compressed gas, causingvery serious results. By providing means for safely and efficientlycarrying much larger supplies of oxygen, suiicient for use by the pilotas well as accompanying passengers over long sustained high altitudeflight, the invention makes commercially possible a type of ying whichheretofore has been more or less experimental in nature.

It will be evident that various modifications in the particularapparatus shown may be made without departing from the spirit of myinvention as defined in the appended claims.

I claim:

1. A liquid oxygen apparatus comprising a liquid oxygen container, asupport in the form of a frame disposed about said container adapted tofreely suspend the container in a constant upright position, heatingmeans within the container for promoting evaporation of the liquidoxygen, means associated with said support for supplying heating energyto said heating means, and means including a portion of said support forconducting oxygen gas from the container to a point of use.

2. A liquid oxygen apparatus for airplanes comprising a liquid oxygencontainer, a support in the form of a frame disposed about saidcontainer adapted to freely suspend the container in a constant uprightposition irrespective of the position of the airplane, a heating coilwithin the container, means including a portion of said support forconducting a heating medium to said heating coil to promote evaporationof the liquid oxygen, and means including another portion of saidsupport for conducting oxygen gas from the container to its point ofuse.

3. A liquid oxygen apparatus for airplanes comprising a spherical liquidoxygen container; a support for said container adapted to freely suspendthe container in a constant upright position irrespective of theposition of the airplane, said support including a hollow circular framein which the container is pivoted; a heating coil within the container;means including a portion of said circular frame for conducting aheating medium to said heating coil to promote evaporation of the liquidoxygen; and means including another portion of said circular frame forconducting oxygen gas from the container to its point of use.

4. A liquid oxygen apparatus for airplanes of the type provided with amotor capable of supplying heat comprising a spherical liquid oxygencontainer; a support for said container adapted to freely suspend thecontainer in a constant upright position irrespective of the position ofthe airplane, said support including a hollow circular frame in whichthe container is pivoted; a heating coil within the container; meansincluding a portion of said circular frame for conducting heat suppliedby the motor to said heating coil to promote evaporation of the liquidoxygen; and means including another portion of said circular frame forconducting oxygen gas from the container to its point of use.

5. A liquid oxygen apparatus for airplanes of the type using an internalcombustion engine comprising a spherical liquid oxygen container; asupport for said container adapted to freely suspend the container in aconstant upright position irrespective of the position of the airplane,said support including'a horizontally pivoted hollow circular frame inwhich the container is suspended on pivots at right angles to thosecarrying the x frame; a heating coilwithin the container; means aboutthe engine exhaust pipe for collecting warm air; means including aportion of said circular frame for conducting air warmed by the exhaustpipe to said heating coil when desired to promote evaporation of theliquid oxygen; and means including another portion of said circularframe for conducting oxygengas from the container to its point of use.

6. A liquid oxygen apparatus for airplanes of the type using an internalcombustion engine having an exhaust pipe, comprising a liquid oxygencontainer, a support in the form of a frame disposed about saidcontainer adapted to suspend the same freely in a constant uprightposition irrespective .lub

